2010 US Open champion Graeme McDowell hailed his opening 69 as one of his best ball-striking rounds, and was pretty content once again despite slipping back over par after a round of 72. He said: "Today wasn't bad either. It's difficult to play the course this way around [McDowell started on the ninth]. I bogeyed three of the last four holes which is disappointing, but I'm making a lot of birdies - relatively speaking, for a US Open - which is nice.

"I putted well but the wind is making it very difficult to get close to the flag. There are similarities [with Pebble Beach, where he won the tournament] - with the wind, and the conditions - but the greens are smaller. I think level par will be good this weekend - they can hide pins and make scoring very tough here."

Luke Donald shot 72 on Friday - but nevertheless missed the cut at 11-over. The world No. 1 said: "It was a little better today, but little consolation obviously. I think I missed nine putts inside 10 feet yesterday and just couldn't get the feel for the greens, the reads, the speed.

"And if I had putted a little bit better yesterday I could have ground out a score today and maybe been somewhere decently placed for the weekend. But it wasn't to be and I'm trying to learn from it and come back stronger next time."

Rory McIlroy's title defence was less than convincing as he fell victim to inconsistent approach play in the opening two rounds. He said: "It wasn't the way I wanted to play. I left myself with a lot of work to do after yesterday's round, and to be honest overall I don't feel like I played that badly for the last two days.

"It's just such a demanding golf course and just punishes the slight test shot that's off line or that's maybe not the right distance or whatever and that's how I feel. I feel like you really have to be so precise out there and if you're going to get punished."

Tiger Woods is firmly in contention after another impressive round as he shot even-par on Friday. He said: "That golf course was some kind of quick. It got dried out. The wind was swirling a little bit out there. It was tough. It was really, really tough. Just had to stay as patient as possibly and I did a really good job that have today.

Jim Furyk was the first man in under-par for 36 holes, beating the course by a single shot. He said: "I got off to a bit of a slow start with the three-putt at the ninth but I collected myself and did the right things. I'm very pleased with one-under. It's hard to get the ball in the fairways here - especially four and five - while the greens are also quite firm.

"Front pins are almost impossible to get the ball close, depending on the setup over the weekend over-par could easily win this tournament. You need to be on top of your game physically, while mentally it's a test of patience."

Nicolas Colsaerts is also one-over after another resilient day's play. He said:" You just got to try to hit the most sensible shot all the time. You just got to, even how good you see the shot, how you feel the shot.

"I thought that my last six, seven holes, which was going to be the toughest ones on that wrong side, were going to keep my round in shape. So I thought if I just parred my way on these it would still look pretty good."

Casey Martin, who needs a golf buggy to get around the course due to a rare disorder with his leg, could make the cut after finishing nine-over. He said: "I think 2006 was [the last] legitimate tournament [he played in], I think. I would have liked to have made that last putt. I know that. I know that eight-over probably was [going to make the cut] for sure. And nine is probably going to be odd man out. But you never know."

Phil Mickelson battled through the second round to make the cut, saying: "My goal was to shoot under par. I had multiple chances and I was fractionally off on the greens. I just didn't make any until the last putt.

"I think the longest putt I made was four feet. It was close though, like they were just a fraction off, missing them bay inch or two. I had a really good thing happen yesterday. I hit balls after the round, and I had this really good breakthrough."

John Peterson, 23, is well placed at one-over for the tournament - but admitted tiredness might be a problem over the weekend. He noted: "It's a tough walk. Two days in a row. It's going to be tough for four.

"I didn't hit it as close as I should have a few times. I kept hitting it to 30 or 40 feet and out here you've just got to lag those, because if you run that thing six or seven feet by, it's going to have a foot of break coming back and it's a tough putt."

After enduring a tricky start to his Manchester United career, perhaps it is fair that Marcos Rojo celebrated so boisterously as he watched his first professional club Estudiantes beat fierce rivals Gimnasia